code: def test_loop_factory(self):
      asyncio.set_event_loop_policy(None)
  
      class TestCase1(unittest.IsolatedAsyncioTestCase):
          loop_factory = asyncio.EventLoop
  
          async def test_demo1(self):
              pass
  
      test = TestCase1("test_demo1")
      result = test.run()
      self.assertTrue(result.wasSuccessful())
      self.assertIsNone(support.maybe_get_event_loop_policy())
  
imports: import asyncio
  import contextvars
  import unittest
  from test import support
label_desc: Use image node_id 15 for calling the TestAsyncCase obj's underlying member method code with example usage: obj.test_loop_factory() without return types